I've got a 2000 Contour where the O/D light flashes upon going up a long grade. Any new revelations in this regard beyond the attached article in Gears?

http://www.atra.com/gears/janfeb02/newKid.html

It was somehow assembled with one of the old black sensors even though it is a newer model. Maybe it was a leftover part that they threw in it since it was the last year.